Ford Lowers Gas Mileage on 6 Models, All 2013-14s

For the second time in less than a year, the Ford Motor Company is lowering the fuel-economy ratings for some of its vehicles.

The automaker said on Thursday that it would reduce the mileage rating on six new models, most of them hybrids, and pay $125 to $1,050 to customers who own or lease about 200,000 of the cars in the United States.

The vehicles include four versions of the 2014 Ford Fiesta, as well as the hybrid and plug-in hybrid versions of the 2013-14 C-Max and Ford Fusion and the hybrid version of the 2013-14 Lincoln MKZ. Most of the vehicles’ combined city and highway rating will be lowered by one to five miles per gallon; the MKZ will be reduced the most, by seven miles per gallon, to 38 from 45.

The announcement came during increasing federal scrutiny of automakers over safety and fuel-economy standards.

Michelle Krebs, senior analyst at AutoTrader.com, said that Ford’s actions came “against two significant backdrops: G.M.’s recall mess, which has prompted all automakers to address issues quickly so as not to be accused of dragging their feet, and automakers addressing fuel economy misstatements.”

Last August, Ford lowered the ratings on the 2013 C-Max hybrid to 43 miles a gallon from 47 in combined city and highway driving. After that announcement, the Environmental Protection Agency said it would update its labeling rules, which date to the 1970s, to resolve disparities among hybrid and electric vehicles.

“We apologize to our customers and will provide good-will payments to affected owners,” Alan R. Mulally, Ford’s chief executive, said in a statement. “We also are taking steps to improve our processes and prevent issues like this from happening again.”

Ford is not alone is overstating the fuel efficiency of its vehicles. In November 2012, after an E.P.A. investigation into consumer complaints that their cars were underperforming, Hyundai and Kia Motors said that they would begin to reimburse consumers and restate gas mileage estimates for about 900,000 vehicles sold in the United States.

The automakers, which are both controlled by the Hyundai Motor Group, set aside about $400 million to settle consumer lawsuits and compensate drivers that were affected by the incorrect ratings.

Christopher Grundler, director of the E.P.A.’s office of transportation and air quality, said Ford notified the regulatory agency of the issue on March 28, after internal testing had revealed the error, and the agency began retesting vehicles with Ford.

“The E.P.A.’s investigation into this matter is ongoing,” Mr. Grundler said. “We are interested and will continue to look for underlying causes of the error.”

Mr. Grundler said that Ford, which was not fined, has agreed to apply stricter standards on fuel economy testing, which would, essentially, require the company to double-check its tests before manufacturing vehicles. Federal regulators are considering rules that would require all automakers to go through this process, he added.

Jack R. Nerad, editorial director at Kelley Blue Book’s KBB.com, said Ford’s action may spur the E.P.A. to be “more directive and restrictive in how its fuel-economy rules and ratings are administered.”

“At the very least we expect tighter auditing of the process, so that substantial discrepancies over a sizable number of vehicles do not occur in the future,” he said in an email. “Certainly this will gain attention in Congress as well.”

Some consumers have taken to online forums to complain about the gas mileage on these models.

In September, one driver of a 2013 MKZ wrote at Edmunds.com that the mileage was “closer to 36 m.p.g.” than the advertised 45.

Jacob Barros, a real estate agent from Phoenix, said his 2014 Lincoln MKZ hybrid averages 33 to 35 miles per gallon. He finds that disappointing, but isn’t too upset. “I’m an automotive enthusiast,” he said. “I love the car in general so it more than makes up for a few miles per gallon.”

Ford has emphasized fuel economy in its marketing. A Super Bowl commercial in February, for example, trumpeted the Fusion hybrid as having “nearly double the fuel economy of the average vehicle.” With Thursday’s announcement, the rating on that vehicle was reduced to 42 miles per gallon from 47.

Christopher Jensen contributed reporting.

A version of this article appears in print on , Section B, Page 3 of the New York edition with the headline: Ford Lowers Gas Mileage on 6 Models, All 2013-14s. Order Reprints | Today’s Paper | Subscribe